反应详情

A solution of 2-tert-butoxycarbonylamino-3-(4′-dibenzofuran-4-yl-biphen-4-yl)-propanoic acid methyl ester (125 mg, 0.24 mmol) in THF (2 mL) and methanol (2 mL) was cooled to 0° C. and treated with 2 N KOH (1.0 mL). After stirring at room temperature for 1 h the solution was acidified with 10% HCl to pH 2 and diluted with ethyl acetate (25 mL). After being seperated, the aqueous layer was extracted with ethyl acetate (3×15 mL) and the combined organic layers were dried over MgSO4 and concentrated. Purification by flash column chromatography (2-5% methanol in dichloromethane) provided 2-tert-Butoxycarbonylamino-3-(4′-dibenzofuran-4-yl-biphen-4-yl)-propanoic acid (80 mg, 67%) as white solid. 1H NMR (CDCl3), 7.98 (d, J=9 Hz, 2H), 7.93 (d, J=8 Hz, 2H), 7.74 (d, J=9, 2H), 7.59 (m, 4H), 7.41 (m, 5H), 5.01 (d, J=8 Hz, 1H), 4.66 (m, 1H), 3.30 (m, 2H), 1.47 (s, 9H). LCMS 408 (M+−100).

1. customAfter being seperated
2. extractionthe aqueous layer was extracted with ethyl acetate (3×15 mL)
3. dry with materialthe combined organic layers were dried over MgSO4
4. concentrationconcentrated
5. customPurification by flash column chromatography (2-5% methanol in dichloromethane)